Weak antilocalization in a strained InGaAs/InP quantum well structure

TL;DR

This study investigates the weak antilocalization effect in a strained InGaAs/InP quantum well, revealing its dependence on magnetic field orientation and gate voltage, and proposing a magnetic field-dependent spin-orbit scattering model.

Contribution

It provides experimental insights into WAL in strained quantum wells and introduces a model where spin-orbit scattering time varies with magnetic field, unlike previous fixed-parameter models.

Findings

WAL depends only on the normal magnetic field component for tilt angles less than 84°

WAL shows non-monotonous gate voltage dependence not explained by Rashba or Dresselhaus mechanisms

Magnetic field influences spin-orbit scattering time, affecting conductivity corrections

Abstract

Weak antilocalization (WAL) effect due to the interference corrections to the conductivity has been studied experimentally in a strained InGaAs/InP quantum well structure. From measurements in tilted magnetic filed, it was shown that both weak localization and WAL features depend only on the normal component of the magnetic field for tilt angles less than 84 degrees. Weak antilocalization effect showed non-monotonous dependence on the gate voltage which could not be explained by either Rashba or Dresselhouse mechanisms of the spin-orbit coupling. To describe magnetic field dependence of the conductivity, it was necessary to assume that spin-orbit scattering time depends on the external magnetic field which quenches the spin precession around effective, spin-orbit related, magnetic fields.